I think that the GOH's convenience trumps the host's convenience (within reason, obviously). Especially when the "host" is really more of an "arranger".
I think the "arranger" part is important here. If the host is actually hosting at their house, or is paying for the meal, then the host and the GOH have equal say, and both have veto power (the GOH doesn't have to go to a party that's really inconvenient, or serves food they can't eat, but the host doesn't have to pay for a party that's at a place they're uncomfortable with, or spend more than they can manage).
When the 'host's' duties are sending out the email about where and when the party is, the GOH's convenience's get a much higher weighting.
In this case, it sounds like Sally was more concerned with her own convenience than that of anyone else, which doesn't make her look good. I do think that if you're sending out the emails, and everyone says "No thanks, we're going out at X time without you" it's pretty tacky. But the flip-side of that is that if you're arranging, you need to listen if people have a problem with your ideas.